Air-cooled belt splicer

Abstract

Cool-down time is menimized by the use of a cooler having integral fins of high surface area, and the use of high-efficiency fans. Heat-up time is minimized by the low mass of the cooler, and the prevention of transmission of heat to the housing.

The invention claimed is: 
     
       1. Belt-splicer, for making splices in conveyor belts, which includes:
 top and bottom housings, structured to have the capability: 
 (a) to be assembled over the belt-ends to be spliced, the maximum-belt-width that can be accommodated by the splicer being MBW meters; 
 (b) during splicing, to enable heat and pressure to be applied to the splice; 
 (c) after splicing, to be separated and removed from the belt; 
 a top platen assembly, which includes: 
 (a) a top pressure surface, being the surface of the splicer that presses downwards against the top of the belt splice during a splicing operation; 
 (b) an operable top heater, which is effective when operated to heat the top pressure surface; 
 (c) a top cooling assembly, which draws heat from the top pressure surface, and thus cools the belt; and the top cooling assembly includes: 
 (c)(i) a top cooler, comprising a top base-plate having top cooling fins; 
 (c)(ii) an operable top air-blower, which is effective when operated to blow cooling air through top spaces between the top fins of the top cooler; 
 a bottom platen assembly, which includes: 
 (a) a bottom pressure surface, being the surface of the splicer that presses upwards against the bottom of the splice during a splicing operation; 
 (b) an operable bottom heater, which is effective when operated to heat the bottom pressure surface; 
 (c) a bottom cooling assembly, which draws heat from the bottom pressure surface, and thus cools the belt; and the bottom cooling assembly includes: 
 (c)(i) a bottom cooler, comprising a bottom base-plate having bottom cooling fins; 
 (c)(ii) an operable bottom air-blower, which is effective when operated to blow cooling air through bottom spaces between the bottom fins of the bottom cooler; 
 an inflatable pressure-bag, and structure for inflating same with a fluid under pressure; 
 the splicer is so structured that, when the pressure-bag is inflated, the top and bottom pressure surfaces are urged together, to apply compression to the splice; 
 a controller, which is effective to enable: 
 first a heat-up phase, in which the pressure-bag is inflated and the top and bottom heaters are operated to raise the belt to a hot temperature; 
 second a timed heat-soak phase, in which the pressure-bag remains inflated and the top and bottom heaters are operated to maintain the belt at the hot temperature; 
 third a cool-down phase, in which the heaters are switched-off, the pressure-bag remains inflated, and the top and bottom air-blowers are operated to cool the belt to a cool temperature; 
 fourth a switch-off phase, when the belt is cool, in which the heaters and the coolers are switched off, the pressure-bag is deflated, and the controller enables the housings to be separated and the splicer to be removed from the now-spliced belt. 
 
     
     
       2. The belt-splicer of  claim 1 , wherein:
 the top air-blower includes a top fan or fans; 
 the top fan by itself, or the top fans together, have the capability to move air at a flowrate of three hundred liters per minute, multiplied by MBW, or more; 
 the bottom air-blower includes a bottom fan or fans; 
 the bottom fan by itself, or the bottom fans together, have the capability to move air at a flowrate of three hundred liters per minute, multiplied by MBW, or more. 
 
     
     
       3. The belt-splicer of  claim 2 , wherein each air-blower is efficient, in that the blower can deliver the said air-flowrate against a pressure head of twenty centimeters of water, upon being supplied with half a kilowatt of electricity or less. 
     
     
       4. The belt-splicer of  claim 2 , wherein each air-blower is a compact fan, in that a housing of the fan:
 (a) has the basically-cylindrical form arising from housing an electric motor which is coaxially in-line with fan-blades; 
 (b) includes a volute-chamber and a tangential outlet-tube for collecting the pressurized air and conveying same out of the fan; 
 (c) has such overall dimensions, over the motor and the volute-chamber, but not including the length of the outlet-tube, that the fan can fit in a cubic box six cm by six cm by six cm. 
 
     
     
       5. The belt-splicer of  claim 1 , wherein:
 the top fins and the top base-plate are monolithic; and 
 the bottom fins and the bottom base-plate are monolithic. 
 
     
     
       6. The belt-splicer of  claim 1 , wherein:
 the top cooler, comprising the top base-plate and the top fins, has been formed from a unitary top block of metal; and 
 the top fins have been created by machining away the spaces between the top fins; 
 the bottom cooler, comprising the bottom base-plate and the bottom fins, has been formed from a unitary bottom block of aluminum; and 
 the bottom fins have been created by machining away the spaces between the bottom fins. 
 
     
     
       7. The belt-splicer of  claim 6 , wherein the metal is aluminum or other metal having a thermal conductivity equal to or greater than that of magnesium. 
     
     
       8. The belt-splicer of  claim 1 , wherein:
 the top cooler, comprising the top base-plate and integral top fins, has a mass of no more than 1.5 kilograms, per meter length of the base-plate; 
 the bottom cooler, comprising the bottom base-plate and integral bottom fins, has a mass of no more than 1.5 kilograms, per meter length of the base-plate. 
 
     
     
       9. The belt-splicer of  claim 1 , wherein:
 the top cooler is so structured that the surface area of the metal of the top base-plate and top fins that is exposed to fan-blown cooling air during the cool-down phase is 2500 sq.cm, or more, per meter length of the base-plate; 
 the bottom cooler is so structured that the surface area of the metal of the bottom base-plate and bottom fins that is exposed to fan-blown cooling air during the cool-down phase is 2500 sq.cm, or more, per meter length of the base-plate. 
 
     
     
       10. The belt-splicer of  claim 1 , wherein:
 a top thermal-tray-assembly of the top platen assembly includes: 
 a top tray of sheet metal, formed as a floor with upstanding side-walls, defining a top cavity therebetween; 
 the top pressure surface being an outwards-facing surface of the top sheet-metal tray; 
 the following components are located in the top cavity, in order, from the floor: 
 the top heater, in the form of a top electrical heating-pad; 
 the top cooler; 
 a top layer of heat-insulating material; 
 a bottom thermal-tray-assembly of the bottom platen assembly includes: 
 a bottom tray of sheet metal, formed as a floor with upstanding side-walls, defining a bottom cavity therebetween; 
 the bottom pressure surface being an outwards-facing surface of the bottom sheet-metal tray; 
 the following components are located in the bottom cavity, in order, from the floor: 
 the bottom heater, in the form of a bottom electrical heating-pad; 
 the bottom cooler; 
 a bottom layer of heat-insulating material. 
 
     
     
       11. The belt-splicer of  claim 10 , wherein:
 the side-walls of the top sheet-metal tray are formed with folded-in lips, whereby the top cavity is at least partially roofed-over, and is constrained as to its height; 
 the top thermal-tray-assembly is so arranged that the said top components slide in/out with respect to the top cavity; and 
 the top components, once assembled into the top sheet-metal-tray, are retained therein, and resist moving with respect thereto, during handling and usage thereof; 
 the side-walls of the bottom sheet-metal tray are formed with folded-in lips, whereby the bottom cavity is at least partially roofed-over, and is constrained as to its height; 
 the bottom thermal-tray-assembly is so arranged that the said bottom components slide in/out with respect to the bottom cavity; and 
 the bottom components, once assembled into the bottom sheet-metal-tray, are retained therein, and resist moving with respect thereto, during handling and usage thereof. 
 
     
     
       12. The belt-splicer of  claim 11 , wherein the top thermal-tray-assembly includes also the following top supplementary layers:
 a top thin film of polyimide, or other electrical insulation material, located between the top heater pad and the top floor; 
 a top thin film of polyimide, or other electrical insulation material, located between the heater pad and the top cooler; 
 a top thermal-evenness layer, located next to the top floor, in which the material of the layer, under the compression provided by the pressure-bag, conforms to the material of the top floor in such manner as to significantly even out differences and gradients of temperature between different points on the floor; 
 a top cover-plate, which engages the tips of the top fins, preventing the escape of air from between the top fins, and constraining the blown-air to pass along between the top fins; 
 and wherein the bottom thermal-tray-assembly includes also the following bottom supplementary layers: 
 a bottom thin film of polyimide, or other electrical insulation material, located between the bottom heater pad and the bottom floor; 
 a bottom thin film of polyimide, or other electrical insulation material, located between the heater pad and the bottom cooler; 
 a bottom thermal-evenness layer, located next to the bottom floor, in which the material of the layer, under the compression provided by the pressure-bag, conforms to the material of the bottom floor in such manner as to significantly even out differences and gradients of temperature between different points on the floor; 
 a bottom cover-plate, which engages the tips of the bottom fins, preventing the escape of air from between the bottom fins, and constraining the blown-air to pass along between the bottom fins. 
 
     
     
       13. The belt-splicer of  claim 10 , wherein:
 the pressure-bag is located in the top housing; 
 the pressure-bag, when inflated, exerts a downwards force on the top thermal-tray-assembly and on the top pressure-surface, and reacts that force by way of an upwards force on the top housing; 
 the top pressure-surface is movable down/up, relative to the top housing, responsively to the pressure-bag being inflated/deflated; 
 the top thermal-tray-assembly is spring-loaded with respect to the top housing, in the direction to collapse the pressure-bag; 
 the bottom pressure-surface remains fixed with respect to the bottom housing when the pressure-bag is inflated/deflated. 
 
     
     
       14. The belt-splicer of  claim 1 , wherein:
 a top thermal-tray-assembly of the splicer includes: 
 a top tray of sheet metal, formed as a floor with upstanding side-walls, defining a top cavity therebetween; 
 the top cooler is located in the top cavity; 
 the top cooler is so arranged that blown air is received into the spaces between the top fins of the top cooler, and the fins split the received air into multiple channels which direct the air along the top cooler; and 
 the top fins are arranged to direct air emerging from the channels out through top openings in the side-walls of the top sheet-metal-tray; 
 a bottom thermal-tray-assembly of the splicer includes: 
 a bottom tray of sheet metal, formed as a floor with upstanding side-walls, defining a bottom cavity therebetween; 
 the bottom cooler is located in the bottom cavity; 
 the bottom cooler is so arranged that blown air is received into the spaces between the bottom fins of the bottom cooler, and the bottom fins split the received air into multiple channels which direct the air along the bottom cooler; and 
 the bottom fins are arranged to direct air emerging from the channels out through bottom openings in the side-walls of the bottom sheet-metal-tray. 
 
     
     
       15. The belt-splicer of  claim 1 , wherein:
 during preparation for a splicing operation, the to-be-spliced ends of the belt are clamped firmly to the bottom-housing, being the housing in which the corresponding pressure-surface does not move; and 
 the belt ends are so arranged in the splicer that, when the pressure-bag is inflated and the top pressure-surface moves towards the bottom pressure-surface, such movement acts to urge the belt ends together. 
 
     
     
       16. The belt-splicer of  claim 1 , wherein the structure of the splicer is such that, at least during the heat-up and heat-soak phases:
 in respect of any top heat-conducting component of the top platen assembly that is in heat-conducting contact with the top heater, there is substantially no heat-conducting contact between that component and the housings of the splicer; 
 in respect of any bottom heat-conductive component of the bottom platen assembly that is in heat-conducting contact with the bottom heater, there is substantially no heat-conducting contact between that component and the housings of the splicer. 
 
     
     
       17. The belt-splicer of  claim 1 , wherein:
 the splicer includes an inflation sub-tray-assembly, upon which are carried an air compressor for inflating the pressure-bag and a tube or hose for connecting to same; 
 the splicer includes a controller sub-tray-assembly, upon which are carried control components and connectors, for receiving signals from sensors, including temperature sensors, and a processor for automatically controlling the phases and operations of the splicer in response to the signals; 
 the sub-tray assemblies are structured and arranged to slide in/out of slideways in the housings. 
 
     
     
       18. The belt-splicer of  claim 17 , wherein:
 the inflation sub-tray-assembly is arranged to slide in/out of a slideway in the top housing; and 
 the controller sub-tray-assembly is arranged to slide in/out of a slideway in the bottom housing. 
 
     
     
       19. The belt-splicer of  claim 14 , wherein:
 the top air-blower includes a top fan or fans; 
 the bottom air-blower includes a bottom fan or fans; 
 in respect of each fan, the fan is mounted into one of the thermal-tray-assemblies in that: 
 an outlet-tube of the fan engages inside a length of semi-flexible tubing; 
 the semi-flexible tubing is a tight fit over a length of rigid tubing; 
 the rigid tubing is cemented to a cover plate, which overlies the fins of the cooler, and the spaces between the fins; 
 the splicer is absent any support for the fan, other than the engagement of its outlet-tube with the tubing.